Method of producing cement from molten blast-furnace slag.



. W. LES SING. METHOD OF PRODUCING CEMENT FROM MOLTEN BLAST FURNACESLAG.

- APPLICATION FILED'AUG. 9, 1913.

1, 1 15 3m Patented 1160211914.

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W. LESSING METHOD OF PRODUCING CEMENT FROM MOLTEN BLAST FURNACE SLAG.

APPLIOATION FILED AUG. 9, 1913.

Patented Oct. 27, 1914.

3 SHEETS-SHEET 2 IS '4' illlull/5 M VENT 01E ATTGDKWS W LESSING. METHODOF PRODUCING CEMENT FROM MOLTBN BLAST FURNACE SLAG.

APPLICATION FILED AUG. 9, 1913. I

Liw ml; 1 Patented Oct. 27, 19m.

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UNITED STATES PATENT @FFKQE.

, 'WILHELM- LESSING, OF MENZENBERG, NEAR-,HONNEF, GERMANY, ASSIGNOR TOMIT- TELRHEINISCHE CEMENTJN'DUSTRIE G.

FEM.

M. B. 11., or ooLoGnE. GERMANY, A

METHOD OF PRODUCING CEMENT FROM MOLTEN BLAST-FURNACE SLAG.

Specification of Letters Batent.

Patented @ct. 2?, 1914.

Application filed August 9, 1913. Serial No. 783,922:

To all 'wizomitmag concern Be it known that I, VVILHELM LESSING, acitizen of the German Empire, residing at Menzenberg, nearHon'nef-on-the-Rhine', in Germany, have invented Method of ProducingCement from Molten Blast-Furnace Slag of'which the following is aspecification. I

My invention relates to the production of cement'from moltenblast-furnace slag, and a primary object is to provide an improvedmethod of disintegrating such slag and sub jecting it to the action ofair, or of air and steam, and thereby making cement.

It has heretofore been known to project highly-heated slag in adisintegrated state through a nearly vertical rotating tube, but in suchan apparatus the disintegrated slag falls too rapidly and the naturaldraft of air which flows through the tube from its lower to its upperend does not act sufficiently on the slag. It is also known to projectmolten slag in a finely divided state through an approximatelyhorizontal rotating tube, but in this apparatus the slag was notdisintegrated by purely mechanical means, but by the aid of a fluid,such as air or steam, and in this case a currentof air or the likeflowed from the upper to the lower end of the tube.

When a current of air is used in the known manner for disintegrating theslag a considerable proportion of slag wool is formed unless the air ismore or less moistened, and this is a troublesome operation as thedegree of moisture must be carefully regulated. On the other hand, jetsof steam and air are also liable to carry relatively large lumps of slagthrough the tube or drum, such lumps being the size of peas orhazel-nuts at the outlet. In this known method the slag or the liketravels through the drum, which may be 15 meters or more in length,togetherwith a hot current of gas and vapor which does not materiallyaid in cooling the slag. Air admitted at the end where the slag entersand drawn out by suction at the, opposite end is heated considerably bycontact with the hot liquid slag at the admission end and travels in itsheated state with the slag. When this hot air or a mixture of othergases and especially sulfurous acid travels in the same di-v rection asthe slag, as in the known methods an Improved of producing cement fromliquid. slag referred to above, it exercises a deleterious actionon theslag.

Another object of my invention is to ob viate these defects of knownmethods.

To these. ends my invention consists in the operations describedhereinafter and pointed out in the claims.

According to my invention I project the molten slag in a disintegratedstate through an approximately horizontal rotary cooled tube or conduitand simultaneously cause a current of air, with or without an admixtureof steam, to flow through the same tube or conduit in the oppositedirection. When making the cement I use, instead of jets of steam orair, a rotary appliance, c. g. a drum or wheel, for purely mechanicallyprojecting the liquid slag in a disintegrated state into thesubstantially horizontal conduit, the liquid slag being poured on to thesaid rotary appliance at the higher end of the conduit. A rotary drum orwheel disintegrates the material much more effectively than a jet of airor steam and without any tendency to produce slag wool and large lumpsof slag, the particles being of-the size of coarse grit. or evensmaller. I admit air into the tube or conduit at the end at which theslag leaves the same, so that the slag and air travel in oppositedirections, the air being discharged through a chimney or uptake at theend at which the slag enters.

Some advantages of the counter-current of air are that it carries withit those vapors and gases which are liberated when the slag isdisintegrated, so that they do not travel through the tube or conduitwith the slag. Secondly, the air introduced cold takes up heat from theslag when traveling through the tube or conduit and greatly acceleratesthe cooling process. This enables the length of the tube or conduit tobe considerably reduced and less driving power is required.Any'admixtures to be used with the slag can be introduced in a dry stateduring the atomizing operation of the rotary drum and the quality of theslag can thus be improved.

While the slag is passing from the one end of the tube or conduit to theother after being disintegrated it is subjected to an addi tiona'ldisintegrating action owing to itsi1n pacting against the ribs providedon internal periphery of the tube or conduit which is preferablywater-cooled and rotated about its longitudinal axis.

Two forms of app ratus adapted for carrying my invention into practiceare diagrammatically represented by way of example in the accompanyingdrawings, where- Figure 1 is a longitudinal section of one form of theapparatus, and Fig. 2 a similar section of the other form, Fig. 3 beinga cross-section on the line A-B of Fig. '2.

Referring in the first instance to theconstruction shown in Fig. 1, tdesignates the cooling drum, at the right hand end of which there is astationary housing It into which the molten slag is introduced by meansof a channel u. The housing It has a chimney 7e and a water jacket 9,and its floor is downwardly inclined toward the floor of the drum twithin which it terminates. A. rotary projecting drum m is arranged inthe housing between the floor and the channel u. The drum t is rotatedby means of worm gear \V and rollers R,

and is externally cooled by means of spraying apparatus 1'. In theinterior of the drum ribs i are provided'for acting on the slag. Theleft hand end of the drum is open, and air drawn in at that end passesout through the chimney or uptake 7a.

In the construction shown in Figs. 2 and 3 the parts designated 9 70 u mare similarto the parts g, 70, a, m in Fig 1, and are arranged at theleft-hand end of a rotary drum t having a water-jacket t whereby it iscooled. In the interior of the drum there are ribs 2', and near thelower end of the drum there are. holes 0, which admit air. The lower endof the drum is closed'byja head I), which has a water-jacket bcommunicating with the water jacket t and provided with a hollowjournalat mounted in a bearing 1. Through the journal n passes a tube 1the joint between same and the journal being made tight by means of astufiing box s The tube 7' serves as a sheath for two bent pipes d and6, both of which are joined to a water gage 2. These pipes extendintothe Water jacket 6 the pipe d being bent upward and terminating inthe steam space above the water levelin the jacket, and the pipe e beingbent downward, and terminating in the water. The pipe 6 is used forfeeding water to the jackets and t, and the pipe (1 conveys steamgenerated in the water jackets to the interior of the drum t. Theadmissi on of steam to the drum renders. the slag more friable and easyto grind.

What I claim'as my invention and desire to secure by Letters Patent ofthe United States is 1. The herein described method of producing cementfrom molten blast-furnace slag consisting in projectingthe molten slagin a disintegrated condition by a mechanical agitator into anapproximately horizontal conduit, and simultaneously causing a currentof air to flow through the conduit in the opposite direction.

2. The herein described method of producing cement from moltenblast-furnace slag consisting in projecting the molten slag in adisintegrated condition by a mechanical agitator into an approximatelyhorizontal conduit, and simultaneously causing a'current of air andsteam to flow through the conduit in the opposite direction.

3. The herein described method of producing cement from moltenblast-furnace slag consisting in projecting the molten slag in a'disintegrated state by a mechanical agitator into anapproximatelyhorizontal rotatory cooled tube, and in simultaneouslyforcing a current of air through the tube in the opposite direction.

In witness whereof I have signed this specification in the presence oftwo witn'esses.

VILHELM LESSING. lVitnesses:

WOLDEMAR HAUP, HENRY HASPER.

